1. Field of the Invention
The present invention relates to flush tank systems, and more particularly to systems of the type in which a tank is repeatedly filled with a fluid such as water and emptied by action of the weight of the water within the tank.
2. History of the Prior Art
It is known in the art to provide flush tank systems of the type which are repeatedly filled with water and are emptied of the water by action of the weight of the water within the tank. In a typical installation the tank which is of elongated configuration and which has an opening extending along the length thereof is mounted at the opposite ends for rotation about a generally horizontal axis. A hose or other discharge device located above the tank opening provides a continuous supply of water to the inside of the tank. The cross-sectional shape of the tank is non-uniform and is configured so that as the water level rises within the tank, the center of gravity of the water shifts. Eventually a point is reached at which the tank suddenly rotates from the upright position into a tipped position in which the opening in the tank moves to the bottom of the tank and the water is quickly discharged through the opening. With the tank emptied the weight thereof causes rotation of the tank back to the upright position. Tanks of this type are useful in a number of applications, such as farm animal waste systems which often require a periodic sudden discharge of a large volume of water. Examples of flush tank systems and related systems are provided by U.S. Pat. Nos. 1,613,640 of Bartosik, 668,853 of Gatling, 228,264 of McFarland and 724,299 of Knobel.
Prior art flush tank systems typically suffer from a number of disadvantages which may make them expensive, may require a substantial amount of maintenance and may greatly shorten their useful life. The bearings which are often required to rotatably mount the tank at the opposite ends thereof are costly at the outset and may require frequent maintenance or periodic replacement. The design of many systems is such that the dumping action requires use of a bumper mechanism to terminate downward rotation of the tank into the tipped position. Moreover, even where an appropriate mechanism is provided to absorb much of the shock of the tank as it comes to rest in the tipped position, the foundation beneath the tank may eventually be damaged or destroyed and the tank itself may be damaged or worn out prematurely. As the tank dumps the water therefrom and returns to the upright position, many systems require arrangements of springs, bumpers and the like to slow down and terminate movement of the tank, thereby adding to the cost and complexity of the system as well as shortening the useful life of the tank. Some prior art designs require that the tank be of generally trapezoidal cross-section. Such tanks typically experience undesirable load stresses under the weight of the water, which stresses often produce bending of the metal of the tank. The support frames on which the opposite ends of the tank are mounted must typically be of very substantial and heavy duty construction and at that are frequently damaged or worn out prematurely because of the lateral forces exerted thereon due to bumping or stopping of the tank as well as the vertical forces due to the weight of the tank and the water.
Accordingly it is an object of the invention to provide an improved flush tank system.
It is a further object of the invention to provide a relatively low cost flush tank system having a minimum of parts, particularly those which are subject to constant wear and replacement.
It is a still further object of the invention to provide an improved flush tank system in which bumpers, springs and other mechanisms are not required in either the tipped or the upright position and in which the forces exerted on the support frames by the tank are substantially exclusively unidirectional in nature.